Personally I would avoid the juice... If your baby is happy to drink plain water then there's really no need to introduce sugary juice - it will be near impossible to get them to drink water then. They really don't need the extra sugar so young and tooth decay in the future

I have not started any juice for my baby, but i do make him homemade apple sauce. i just puree steamed apples and once i begin introducing juice, i plan to use a juicer with fresh fruit. I however dont see anything wrong with using the store brought items as i know for sure there is no added sugar in the applesauce, but not sure about the juice